Weekly Weather: Rainy, then cool, then quite warm

Good morning and welcome to my weekly weather report on the immediate past, present and future of weather in the Bayou City.

PAST

Houston’s dry fall continued during the last week, with most of the area getting no, to a few hundredths of an inch of rainfall. It’s now been more than three weeks since the city of Houston officially recorded more than 4 hundredths of an inch of rain on a single day.

As I’ve written, much of the Houston region has slipped back into a moderate drought, and it’s not hard to understand why.

Since Aug. 1, many sites in Houston have received less than half the amount of average rainfall they normally would have received. Here’s a graphic from the National Weather Service that illustrates this for the four primary weather stations in the Houston metro region:

(National Weather Service)

As I’ll discuss below, the Houston region has its best chance of rain since early November this evening. We really need the wet stuff, so let’s hope it comes in greater abundance than presently forecast.

Anyway, let’s do the numbers for last week.

Date

High T

Low T

Average

Departure

Rainfall

Monday

75

45

60

-1

0.00

Tuesday

79

49

64

+3

0.00

Wednesday

83

52

68

+8

0.00

Thursday

77

50

64

+4

0.00

Friday

78

53

66

+6

0.02

Saturday

66

43

55

-5

0.00

Sunday

75

39

57

-3

0.00

Average

76.1

47.3

62.0

+1.7

0.02

Houston has a chance to record its third month with below-normal temperatures this November, with temperatures just a few tenths of a degree above normal right now. It all depends upon how strong the front coming through tomorrow will be.

But the main news is the possibility of rain this evening and tonight. A cold front, now draped across west Texas, is moving toward the upper Texas coast. At the same time an atmospheric feature known as a shortwave trough, essentially a low pressure system in the upper atmosphere that allows air at the surface to rise, is moving toward Texas from the north-northwest.

This upward movement of surface air will allow our region’s warm, moist air to rise, condense and, hopefully, return to us in the form of rainfall.

There is a 60 percent chance of rain showers tonight, say forecasters with the Houston/Galveston office of the National Weather Service, with 6 p.m. to midnight as the hours of the highest likelihood.

Unfortunately most of the area, at this time, appears unlikely to see more than about one-quarter of an inch of rain.

The National Weather Service also says there is a slight risk of severe thunderstorms mainly north of Interstate 10 and east of a College Station to Katy line. The primary threats are hail and damaging wind gusts from around 5 p.m. Monday to 3 a.m. Tuesday.

Tonight's severe weather threat. (National Weather Service)

Forecasters expect the front to push off the upper Texas coast around 6 a.m. Tuesday, so tomorrow morning should be breezy and cool.

After lows in the mid- to upper-40s on Tuesday and around 50 on Wednesday night, temperatures will be warm heading into the weekend. There’s also a chance that another shortwave trough will move across the region on Thursday. This could provide us with another chance of rain.

By the weekend it will be unseasonably warm. Look for highs around 80 and lows in the low 60s. Those lows could be about 12 to 15 degrees above normal for early December.

FUTURE

The average date of Houston’s first freeze at Bush Intercontinental Airport is Nov. 30,according to the National Climatic Data Center. Houston has gotten as cold as 38 degrees this year (twice in November), but we’re going to miss that date.

Although they show a front during the first week of December, long-range models indicate very low chances of freezing temperatures through the first 10 days of December, at least.

Depending on your perspective, that’s a good or a bad thing.

SUMMARY

This week’s scale goes from 0 to 70, the age, in years, of Robertson Stadium at the University of Houston. It will be demolished and replaced with a state-of-the-art facility in time for the 2014 football season.

My number: 59

Finally, if you want several daily updates on weather, please “like” my SciGuy Facebook page. It’s the best place for multiple daily updates on our weather, delivered right to your news feed.

FINE PRINT

As always, thank you to the fine professionals at the National Weather Service for the information and data that make this weekly blog entry possible. Also, bear in mind there’s always uncertainty in weather forecasting, particularly the timing and intensity of precipitation.

Hanging decorations when it’s 80 degrees outside sure does take some of the cheer out of the season. My pessimism tells me it’ll be shorts weather for Christmas. At this point I wonder if my Aran sweater will ever see the light of day again!

I see that you are still using the weather “number”. Will you be changing methods now that the original numerical proponent, Gene Norman, is no longer offering his “Norman Number”? I enjoyed Gene. Any idea why he resigned?